Carbon nanotube sensor detects glucose in saliva

May 3, 2013

(a) Schematic of the experimental geometry. (b) Illustration of glucose binding to a nanotube functionalized with pyrene-1-boronic acid. (c) Bound glucose forms a boronate anion complex that has electrostatic effects on the nanotube FET. (Credit: Mitchell B. Lerner et al.)

Painful finger-prick blood tests for diabetics could become a thing of the past, say physicists who have built a sensor that measures glucose in saliva.

Mitchell Lerner at the University of Pennsylvania and associates have developed just such a device, MIT Technology Review reports. Their glucose sensor is essentially a carbon nanotube-based transistor in which the nanotubes are coated with pyrene-1-boronic acid molecules that bind to glucose.

The device is relatively simple. It’s straightforward to measure the switching characteristics — the current-voltage curve — of a transistor. When glucose binds to the functionalised nanotubes, it simply changes this curve in a measurable way producing a straightforward way to measure glucose concentration.

Carbon nanotube-based sensors could also be significantly cheaper and more robust than the enzyme-based ones that are commonly available today.